Hi Paul,
Look at this small sample.
DataItem class represents some external data. I added the Enabled and Visible properties to keep everything simple, but you may need to use converters.
C#
public class DataItem
{
  public bool Enabled { get; set; }
  public Visibility Visible { get; set; }
  public string Name { get; set; }
}
private void xob_Loaded(object sender, RoutedEventArgs e)
{
  ObservableCollection<DataItem> c = new ObservableCollection<DataItem>();
  c.Add(new DataItem { Name = "A", Enabled = true, Visible = Visibility.Visible });
  c.Add(new DataItem { Name = "B", Enabled = false, Visible = Visibility.Visible });
  c.Add(new DataItem { Name = "C", Enabled = true, Visible = Visibility.Collapsed });
  c.Add(new DataItem { Name = "D", Enabled = false, Visible = Visibility.Collapsed });
  xob.GroupsSource = c;
}
XAML 
<igOB:XamWebOutlookBar x:Name="xob" Grid.Column="1" Loaded="xob_Loaded"> 
  <igOB:XamWebOutlookBar.GroupHeaderTemplate>
    <DataTemplate>
      <StackPanel Orientation="Horizontal">
       <TextBlock Text="{Binding Name}"/>
      </StackPanel>
    </DataTemplate>
  </igOB:XamWebOutlookBar.GroupHeaderTemplate>
  <igOB:XamWebOutlookBar.GroupContentTemplate>
    <DataTemplate>
      <StackPanel>
        <TextBlock Text="{Binding Name}"/>
        <TextBlock Text="{Binding Enabled}"/>
        <TextBlock Text="{Binding Visible}"/>
      </StackPanel>
    </DataTemplate>
  </igOB:XamWebOutlookBar.GroupContentTemplate>
  <igOB:XamWebOutlookBar.DefaultGroupsContainer>
    <DataTemplate>
      <igOB:OutlookBarGroup IsEnabled="{Binding Enabled}" Visibility="{Binding Visible}"/>
    </DataTemplate>
  </igOB:XamWebOutlookBar.DefaultGroupsContainer>
</igOB:XamWebOutlookBar>
Regards,
Marin